Coverage Analysis Skill

Test coverage analysis and improvement strategies.

When to Use

Use when analyzing or improving test coverage.

Running Coverage

# Basic coverage
go test -cover ./...

# Generate coverage profile
go test -coverprofile=coverage.out ./...

# HTML report
go tool cover -html=coverage.out

# Function-level coverage
go tool cover -func=coverage.out

Interpreting Coverage

github.com/user/project/service/user.go:15:   GetUser         80.0%
github.com/user/project/service/user.go:25:   CreateUser      100.0%
github.com/user/project/service/user.go:35:   DeleteUser      0.0%
total:                                         (statements)    75.5%

Coverage Goals

• 70-80% - Good baseline
• 80-90% - Excellent
• 90%+ - Diminishing returns
• Focus on critical paths
• Don't chase 100%

CI/CD Integration

# GitHub Actions
- name: Test with Coverage
  run: |
    go test -v -coverprofile=coverage.out ./...
    go tool cover -func=coverage.out

Best Practices

• Track coverage trends
• Cover critical paths first
• Don't ignore edge cases
• Quality over quantity